Electrical relay



Nov. 8, 1932. N. c. SHAW ELECTRICAL RELAY Filed Dec. 5, 1930 fnsalalion INVENTOR M 4. Shaw,

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M a ATTORNEY.

Patented Nov. 8, 1932 UNITED STATES PAL-1: OFFICE NOBLE C. SHAW, OF SWISSVALE, PENNSYLVANIA, ASSIGNOB TO THE UNION SWITCH & SIGNAL COMPANY, OF SWISSVALE, PENNSYLVANIA, A CORPORATION OF PENN SYLVAN IA ELECTRICAL RELAY Application filed December 5, 1930. Serial No. 500,293.

My invention relates to electrical relays, and has for an object the provision of a relay having at least two front contacts, one of which is closed when the relay is energized 5 by current of one value, and the other of which is closed when and only when the relay is energized by current of a higher value.

I will describe one form of relay embodying my invention, and will then point out the 1; novel features thereof in the claim.

The accompanying drawing is a view showing, partly in side elevation and partly sectioned, one form of relay embodying my invention.

,3 Referring to the drawing, the reference is 20, in which an armature 1 is pivotally mounted at 2. An intermediate stop 3 is also pivoted at 2 in the brackets 20 and is biased by a spring 10 to engage a shoulder 9 on a screw 9 projecting downwardly from the plate A. The spring 10 is compressed between the stop 3 and the lower end of a screw 11 passing through the top plate A. The armature 1 is provided with a pin 7 which coacts with a similar pin 8 in the stop 3, and the armature is also provided with pins 5 which coact with core pins 6 in the pole pieces 4. The armature 1 carries two insulation studs 21 and 22, and attached to these studs are two contact members 17 and 15, respectively. Contact member 17 coacts with a back contact member 19 and also with a front contact member 18, whereas member 15 coacts with a second front contact member 16.

4,; It follows that the relay is provided with a back contact 17-19, a first front contact 17-18, and a second front contact 1516.

When the magnet M is deenergized, the armature 1 occupies a fully retracted position, wherein the back contact 1719 is closed and both front contacts are open. When magnet M is energized by current of a relatively low value, armature 5 is attracted to an intermediate position wherein the pins 7 and 8 are in engagement, but the force exerted on the armature is not suflicient to compress the spring 10. Front contact 1718 is then closed, but contact 1516 is still open. The parts of the relay then occupy the positions in which they are illustrated in the drawing. When the magnet M is energized by current of a relatively high value, the force which this magnet exerts on the armature 1 is sufficient to compress the spring 10 until the pins 5 engage the core pins 6. Armature 1 is then in its fully attracted position, and when in this position, front contact 1516 is closed.

The intermediate position of the armature 1 may be adjusted by turning the screw 9 through the medium of a head 14:, and this screw can be locked in its adjusted position by a lock nut 13. The current value required to close the armature 1 to its fully attracted position may be adjusted by turning the screw 11, whereupon this screw may be locked in its adjusted position by a lock nut 12.

Although I have herein shown and described only one form of relay embodying my invention, it is understood that various changes and modifications may be made therein within the scope of the appended claim without departing from the spirit and scope of my invention.

Having thus described my invention, what I claim is:

A relay comprising an operating electromagnet, an armature biased by gravity to a fully retracted position and movable to an intermediate position against the force of gravity when said magnet is supplied with current of a relatively low value, means including a spring for preventing the further movement of said armature to its fully attracted position unless said magnet is supplied with current of a relatively high value, a first contact closed when said armature occupies its intermediate position, and a second contact closed when said armature occupies its fully attracted position.

In testimony whereof I aflix my signature.

NOBLE O. SHAW. 

